The present invention, in some embodiments thereof, relates to a mechanical boom deployable in water and, more particularly, but not exclusively, to an inflatable boom designed for rapid deployment at the site of accidental spillage of oil or other environmentally destructive floating materials. The environmental depredations and economic damage caused by oil spills are, unfortunately, well known. Methods generally employed today to deal with accidental old spills and similar situations generally involve towing, to the site of the spill, a large mechanical boom (e.g. a floating oil barrier) which comprises a flotation element which keeps the boom on the surface of the water, and a heavy ballast hanging below the flotation element to provide a wall-like vertical extension reaching below the level of the oil spill. Because such booms are both heavy and cumbersome and because they require relatively large and trained crews to deploy, the booms are not stored in significant lengths at potential spill sites but rather at central locations or at facilities specialized in oil spill response. Such booms, when deployed in time, sometimes successfully contain spilled oil (or other damaging spilled materials). However, since these booms sometimes need to be brought by towing (so relatively slowly) and often from relatively distant sources, booms currently in use today sometimes require a great length of time from the moment a spill is discovered to the moment that boom is brought into play to contain the spilled material. In the interval, while waiting for the boom to arrive on site, the spilled material spreads out over the surface of the water, may be churned by waves, driven by winds, moved by currents, and generally tends to extend to large surface areas. These large surface areas then need to be partially surrounded by a boom to start treating the spill. The more time it takes for the boom to arrive on site, the longer the boom needed, and the longer the boom deployment procedure will take. In some cases, while waiting for the boom to arrive, the spill sub-divides into many small separated spill areas, which then must be treated individually. Indeed, in some spill scenarios, arrival of boom equipment to the spill site happens at such a late stage that the arriving booms, instead of being deployed to surround the spill, are deployed near beaches to protect the beaches from the uncontained drifting oil.
Booms in common use today typically comprise a heavy ballast material hanging below a flotation element, and generally are transferred from a storage area to a spill site. The towing process is necessarily slow, especially when there is need, as often happens, to tow the boom in a direction perpendicular to the boom surface, for example to approach the boom to a spill area or to tow spilled material trapped by the boom. Such booms, being bulky, are typically stored in central locations not necessarily in proximity to likely spill sites. The towing or other deployment process generally requires the boom to be built from very durable materials and to incorporate elements that will withstand the towing forces. In addition, large and generally powerful ships are needed to tow the boom portions and/or to otherwise deploy the boom. Finally, current booms typically require large crews that were trained extensively at operating the machinery. The need for a crew adds additional time to the process, since before the booms can be deployed, the crew needs to be gathered and brought to staging location. All these characteristics of conventional containment booms combine to produce a situation where booms usually cannot be rapidly deployed at spill sites, resulting in extensive spreading of the spilled material before the boom containment procedure can even be begun. As a result, containment is sometimes impossible, sometimes only partial or otherwise ineffective, and always expensive, and recovery or treatment of the spilled material is often partial at best.
Some attempts have been made to provide booms which do not need to be towed to a spill site. For example, U.S. Pat. No. 5,197,821 to Richard E. Cain et al., filed in 1991, describes an accordion folded uninflated boom curtain comprising a self-inflating flotation chamber inflated by gas on one longitudinal edge with an integral depending curtain terminating in a self-inflating ballast chamber inflated by the water or sea water on the opposing longitudinal edge. However, Cain's invention has apparently proven ineffective, as witnessed by the fact that it is not generally used in spill containment.
Additional background art includes                U.S. Pat. No. 5,074,709 filed Dec. 24, 1991,        U.S. Pat. No. 5,040,918 filed Apr. 23, 1990,        U.S. Pat. No. 5,120,159 filed Mar. 25, 1991,        U.S. Pat. No. 3,563,036 filed Sep. 2, 1969,        U.S. Pat. No. 5,580,185, Filed Oct. 30, 1995,        U.S. Pat. No. RE28,966 filed Jan. 24, 1974,        U.S. Pat. No. 5,238,327 filed Apr. 9, 1992,        U.S. Pat. No. 4,124,981 filed Sep. 29, 1977,        U.S. Pat. No. 5,885,451 filed Oct. 31, 1990, and        U.S. Pat. No. 4,997,745 filed Dec. 29, 1989.        